The present invention relates to a spring manufacturing apparatus, and more particularly, to a spring manufacturing apparatus for manufacturing various shapes of springs by forcefully bending, winding, or coiling a wire with a tool while continuously feeding the wire to be formed into a spring.
For instance, Japanese Patent No. 2551525 discloses a configuration in which a housing, rotatably supporting a pair of rollers for feeding a wire to be formed into a spring, is made revolvable around a wire axis line, and the rollers are rotated by a worm axis which is off-centered from the wire axis line and a worm wheel which meshes with the rollers.
However, since the worm and worm wheel are rotated at high speed when manufacturing a spring, cooling processing is necessary due to heating problems. Furthermore, because of the heat, a great amount of energy is lost, causing a problem of poor energy efficiency. Moreover, a worm gear is generally used for the mechanism which requires a large speed reduction ratio, represented by e.g., a jack, thus is not suitable for numerical control which requires precision. Furthermore, a predetermined wire feeding force must be maintained even while energy is lost by the heat. For this reason, better durability is necessary, requiring a high cost.